1. Field of Invention
The present invention relates generally to pneumatic tires and more specifically to tires designed for racing and even more specifically to go-kart racing tires.
2. Description of the Related Art
Tire designers have often varied the aspect ratio of tires to achieve various performance parameters. In high performance tires, and those designed for racing, low aspect ratio tires have been favored. For example, U.S. Pat. No. 4,209,050 discloses a tire for high speed vehicles having an aspect ratio of 0.25 to 0.75 and a carcass construction composed of at least two plies with cords inclined at an angle of 20 degrees to 40 degrees with respect to the equatorial plane of the tire. Additionally, U.S. Pat. No. 4,112,994 discloses a pneumatic tire, particularly a high speed motorcycle tire, which has an aspect ratio of less than 0.65 and carcass plies which form an angle with the equatorial plane of the tire of less than 22 degrees.
In some low aspect ratio tires, a problem called "reverse curvature" was encountered. The term "reverse curvature" refers to the tendency of carcass cords in the crown region of the tire to dip radially inwardly at the equatorial plane. This deformation creates points of inflection which are prone to premature failure. One objective of the current invention is to design a low aspect ratio tire which provides excellent handling and durability, especially for racing purposes, but resists the tendency to exhibit reverse curvature.